7208668138 has 16 divisors (see below), whose sum is σ = 12422421504. Its totient is φ = 3073253040.

The previous prime is 7208668133. The next prime is 7208668139. The reversal of 7208668138 is 8318668027.

It is a junction number, because it is equal to n+sod(n) for n = 7208668091 and 7208668100.

It is not an unprimeable number, because it can be changed into a prime (7208668133) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1345245 + ... + 1350592.

It is an arithmetic number, because the mean of its divisors is an integer number (776401344).

Almost surely, 2^7208668138 is an apocalyptic number.

7208668138 is a deficient number, since it is larger than the sum of its proper divisors (5213753366).

7208668138 is a wasteful number, since it uses less digits than its factorization.

7208668138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2696037.

The product of its (nonzero) digits is 774144, while the sum is 49.

The square root of 7208668138 is about 84903.8758714819. The cubic root of 7208668138 is about 1931.7533654120.

The spelling of 7208668138 in words is "seven billion, two hundred eight million, six hundred sixty-eight thousand, one hundred thirty-eight".